Method of producing combined asbestos and glass fiber yarns



7 A Fe); 4, 1941. D. c. SIMPSON 2,230,271

METHOD OF PRODUCING COMBINED ASBESTOS AND GLASS FIBER YARNS- Original Filed May 22, 1937 Donald C. Simpson 7 INVENTOR BYM A ORNEYS Patented Feb. 4, 1941 2,230,271 UNITE-D STATES PATENT OFFICE METHOD OF PRODUCING COIVIBINED AS- BESTOS AND GLASS FIBER YARNS Donald 0. Simpson, Newark, Ohio, assignor, by

mesne assignments, to Owens-Corning Fiberglas Corporation, Toledo, Ohio, a corporation of Delaware Original application -May 22, 1937, Serial No.- 144,24'l. Divided and this application August 24, 1938, Serial No. 226,506

8 Claims.

The present invention relates to methods of combining asbestos and glass fibers for use in yarns, interwoven cloth, knitted articles, felts, or other fabricated articles, particularly adapted for electrical insulation, packing material, gaskets, friction elements, heat insulation, cements, fillers in fabricated boards, acoustical insulation,battery separators, and various other uses. This application is a division of the co-pending Simpson application Serial Number 144,247 filed May'22, 1937, on which U. S. Patent No. 2,132,702 was granted October 11, 1938.

Both glass and asbestos fibers taken by themselves have inherent shortcomings which limit their application and use in industry and commerce. Asbestos, for example, is composed of relatively short and weak fibers which prevent them from being fabricated into strong yarns, cloth, and fabrics. Short asbestos fibers have fall apart. Merely reducing the diameter size of the glass fibers does not necessarily cure this condition because, as the fiber diameter is reduced, so is the radius of curvature around which the fibers have tobe bent. That is to say, the fibers of the warp are bent around the fibers of the filler and if they are bent around a small enough radius of curvature, the fibers of the warp are cracked and broken. The same condition, of course, obtains when the fibers of the filler are bent around the fibers of the warp.

' Another difliculty caused by the inherent nonstretchability of the glass fibers, is the concentration of stresses induced in the outermost fibers at a fold or fiexure in the cloth. The glass fibers being more or less unyielding in and of themselves, prevent the load caused by a fiexure or creasing from being distributed uniformly throughout the body of fibers to permit their full not been fabricated into any type of yarn or fabcombined strength to be brought into play.

rics without the incorporation of organic fibers I have discovered that the above mentioned insuch as cotton, or the like, which serve to hold divldual shortcomings of the asbestos and glass the short asbestos fibers together. Fine wires fibers may be overcome by a combination of the have also been used for this purpose. Both of two, and that a superior product, having properthese additional components, however, have defities superior to any of the individual properties of.

nite shortcomings and disadvantages, as, for exthe ingredients, may be producedby a combina ample, the admixture of organic cotton fibers or tion of the two types of fibers. the like immediately brings down the tempera- An object of the invention is the provision of a ture or fire resistance of the fabric to that of cotfabric which is flexible, soft, St a d 30 ton. The incorporation of wires, on the other pl y fir p e resisting, r p n hand, prevents the use of the product as an elecchemically resistant.

trical insulation. The use of metal wires or the Another object of the invention is the provision like is also inferior from the point of view of pliof a fabric composed of inorganic fibers which ability, flexibility, cost, ease of manufacture, and may be fabricated into felt or interwoven tape 35 feltabilit between the metal wires and the assuitable for electrical, heat and/or sound insulabestos. tion.

Ordinary glass fibers also have serious short- Another object of the invention is to utilize the comings and limitations in their fabrication into softness, pliability and yieldability ore natuwoven fabrics. These limitations are generally rally inherent in the asbestos fibers in combinatraceable to the inherent nonstretchability of tion with glass fibers, which are, much stronger glass fibers, the stretchability being limited to and longer than the asbestos fibers. The indione or two percent ,or so, according to the exact vidual glass fibers are sufficiently fine and long fiber diameter, the type of glass, and the perfecso that they may be intertwisted or interfelted tion of the fiber. When a-series of glass threads with the asbestos fibers to form strong yarns are fed into a conventional loom to form a warp, which may be safely subjected to the rigors of a the sudden stresses and loads inherent in a loom conventional loom. The asbestos fibers serve as are concentrated in thetightest threads which cushions for the adjacent glass fibers to assist cannot carry the entire load themselves and, in the distribution of loads throughout the glass therefore, tend to break rather than stretch. Of fibers, and to lend yieldability and pliability and 50 course, whenever an end or thread breaks in a strength to the final fabric.

loom, the entire operation must be stopped and In addition, if the glass fibers have been interthe broken end fed through again before the twisted or interfelted with the asbestos fibers, weaving may be resumed. A similar condition this arrangement will prevent the individual glass exists when ordinary glass yarns or threads are fibers from being laid out in straight lines, but, so fed into the weft or filler of a fabric. Moreover, on the contrary, will permit them to assume helifabrics composed solely of glass fibers, especially cal, spiral, or undulating paths which serve to if made particularly sheer or thin, have considerprovide a marked increase in the stretchability ably less resistance to folding or creasing than and pliability for the yarn and-fabric produced ordinary fabrics. If the fabric is flexed to any thereby. degree, or creased, it tends to crack or break and As another feature in the present invention, it

is to be noted that the asbestos fibers lying interjacent the glass fibers are softer and inhibit mutual scratching and breakage of the glass fibers as they are bent, flexed, or caused to .move relaoutwardly projecting curled ends which assist in the interfelting and mutual seizure of the glass and asbestos fibers. Moreover, asbestos fibers appear to be more slippery and in this manner assist in distribwg the stresses among the fibers more equally. I Other objects and advantages of the present invention will become apparent from the following description taken in conjunction with thedrawing, in which:

Fig. 1 is an elevational diagrammatic view of an apparatus adapted to produce yarns composed of asbestos and glass fibers;

Fig. 2 is a fragmentary diagrammatic plan view of 'a portion of the apparatus illustrated in Fi 1;

Fig. 3 is a fragmentary elevational diagrammatic view of another form of apparatus adapted to produce yarns composed of asbestos and glass fibers; V

Fig. 4 is a fragmentary'diagrammatical elevational view of a modified embodiment of the presinterfelted into a relatively hard yarn, and it is also possible to use longer fibered asbestos which may be carded and felted into a softer, more pliable type of yarn with the glass fibers. There are also various types of glass fibers which may be used, although I preferably use a fiber having a fine diameter, ranging in the neighborhood'of about .0001 inch .to about .0004 inch for softer,'

more pliable yarns and fabrics. Fibers having larger diameters ranging-up to about one-thou sandth of an inch may also be used for certain products. Fibers having diameters ranging-from about .00015 to .00025 inch have excellent properties inasmuch as they are extremely flexible,

' and free from brash or skin irritation, and, at the same time, are not so fine that the cost or speed of manufacture is prohibitive. However, finer fibers than this, having even more flexibility and feltability, produce excellent fabrics when compounded with the asbestos fibers. The length of the glass fibers also is important, especially since the asbestos fibers are limited in length and of themselves limit the mass integrity and strength of the yarn. However, by using relatively long glass fibers, it is possible to produce yarns in which the principal tension loads are carried by the glass fibers and are distributed over a considerable length of these fibers. Accordingly, I preferably use glass fibers having average lengths at least about one inch and preferably many inches or feet, or even fibers which are theoretically unlimited in length, as may be produced by certain methods of manufacture.

In producing yarns of combined asbestos and glass fibers, it is possible to pick them apart and intermix them together with a carding machine which serves .to straighten out and comb the fibers and intermingle them with one another from where they may be fabricated into intertwisted yarns in which the fibers are more or less interlaced and bound up with one another, the glass fibers providing the principal source of strength and fiber length, and the asbestos'fibers providing the principal source of yieldability and softness, and serving to. distribute the stresses placed in the yarn so that they may be carried more or less uniformly by the individual glass fibers.

If desiredfcertain binders and/or adhesives such as starches, asphalt, waxes, latex, rubber, gelatins, oils, synthetic resins, varnishes, shellacs, stearine, pitch, soaps, casein, cellulose derivatives, or the like, maybe applied to the yarns in accordance with, the particular purpose to which the yarns are to be put. The yarns may also be interwoven into fabrics having any desired construction, and the fabrics may be composed of any desired number of plys, also in accordance with the particular purpose to which it is to be put as, for example, brake lining, packing or gasketing material, clutch facings, electrical insulation, battery separators, or theflike.

In compounding the fibers into yarns, I may first produce a. thread of glass fibers. The fibers of'such threads may be formed, for example, by

the method and apparatus illustrated and described in the British Patent Number 482085. If desired, the yarn formed of this type of glass fibers, which are substantially continuous, may then be coated with a suitable adhesive or binder material and then coated with asbestos fibers which are introduced and combined with the glass yarn by means of a doffer belt upon which the asbestos fibers lie. In order to more perfectly felt the asbestos fibers over the glass yarn, it is sometimes desirable to twist the glass yarn simultaneously as it is being drawn past the doifer belt. Various methods of this type of incorporation, when used with cotton fibers, have been illustrated and described, for example, in the Heany Patents Nos. 1,155,812, 1,155,813, and 1,071,676.

A yarn made in accordance with this method is illustrated in Fig. 8 in which reference character ll designates a yarn composed of glass fibers having a covering l2 of intermatted asbestos fibers.'

It is also possible to use for the yarn II a glass sliver composed of a multiplicity of glass fibers which are more or less mutually intermatted, and which lie predominantly parallel with one another although incompletely so, as illustrated and described in the French Patent Number 814,149. Such a sliver of glass fibers may be coated with an adhesive and have a body of asbestos fibers intermingled and interfelted therewith to produce a yarn in accordance with the present invention.

As illustrated in Fig. 9, I may also produce yarns composed of combined glass and asbestos fibers by intertwisting asbestos paper or felt I3 with threads I4 composed of fine, long, glass fibers, here again the glass fibers serving to carry the load of the yarn .as a whole, and the intertwisted asbestos strip of paper or felt serving to form a cushion for the glass yarn, which is ordinarily nonstretchable. When using such a combination for a friction element or fabric, it may be desirable to pull theglass threads so as to be embedded more or less into the intertwisted asbestos paper or felt, leaving the asbestos fibers exposed more predominantly on the outer surface of the yarn where it may serve as the primary friction element.

Another method of incorporating asbestos and glass fibers into yarns is illustrated in Fig.6 and involves producing asbestos yarns or rovings 40 in the conventional manner and intertwisting these with the yarns 4| composed solely of glass fibers. Ordinarily, the asbestos yarns are not composed of pure asbestos fibers, especially if the asbestos is of the short fiber variety, in which case a small amount of organic fibers, such as cotton, wool, hemp, jute or the like, is incorporated therein in order to provide strength to the yarn during fabrication. In this event, the presence of the organic fibers does not hinder the temperature resistance of the finished fabric after it has been combined with the glass fibers, for in this event the glass fibers are' present and may carry the tensile load even though the organic fibers may be burned out or otherwise destroyed as, for example, by acid, rotting, or the like. In other words, the use of the organic fibers is principally for the purpose of assisting the fabrication of the article rather than being present as a. required element after the fabric has been completed.

As another method of incorporating asbestos fibers directly in with the glass fibers to produce a yarn, I may use the apparatus illustrated in Fig. 1 in which reference character l5 designates an apparatus for attenuating a multiplicity of glass fibers by gaseous mediums, such as steam, air, or the like. This apparatus I5 may be con structed and operated in accordance with the disclosure in the Slayter and Thomas United States Patent No. 2,133,236. Mounted under the forming apparatus I5 is a collecting device It composed of a traveling screen or perforated surface H, which may may be mounted upon an open ended hollow drum l8, revolving upon the shaft l9. Extending into and mounted within the drum l8 and underneath the upper portion of the screen I! is a suction chamber adapted to draw the gases emanating from the forming apparatus I5 and serving to retain the fibers 2| in matted formation more firmly upon the screen II. A blower or other suction means 22 may also be Provided in conjunction with the suction chamber 20 and serves to exhaust the gases from the chamber.

After the fibers have been arrested upon the belt or screen I! in the form of a web 30, they are drawn therefrom into sliver form or yarn 23 through the trumpet or guiding device 25, and then over the rotating spool 26 where they are collected into a package. The roll 21 may be used in order to change the direction of the yarn 23, although in practice this is unnecessary A traversing eye or trumpet 28 may also be provided in order to traverse the yarn across the spool 26 and thus form a uniformly built up package.

Arranged under the web 30 of the fibers as they are being drawn into a sliver, is a doifer belt'3l leading from a suitable asbestos carding device (not shown) and conveying a multiplicity of asbestos fibers 33 arranged and combed in more or less parallel longitudinal position upon the belt 3|, whereby they may be introduced termatted with the web 50.

like.

into the web 30 of glass fibers and incorporated therein to form a mutually interfelted product of combined glass and asbestos fibers. With this arrangement, it will be noted that prior to the incorporation of the asbestos fibers with the glass fibers, the latter are open and in an arrangement facilitating the incorporation of the asbestos fibers. From here the glass fibers are drawn 'or drafted into a more compact strand 23, the adjacent glass fibers being drawn together, closing up the intervening spaces, and permitting the interjacent asbestos fibers to be seized and interfelted therewith in a compact, mutually interfelted coherent strand. To accomplish this interfelting and compacting of the strand, a drafting of several times is generally used. This strand 23 is then drawn through the trumpet and wound upon the spool/26 from which it may be unwound and, if desired, twisted into a more compact denser yarn.

If desired, a spray gun 35 may be provided at any suitable point as, for example, over the web 30, in order to apply a suitable binder or adhesive to the fibers of the finished yarn.

If desired, the strand of combined asbestos and glass fibers may also be drafted by suitable drafting means and a plurality of the yarns, drafted or not, may be intertwisted to form ply yarn such as the one illustrated in'Fig. 5.

Referring now to Fig. 3, I have illustrated a modification of the apparatus shown in Figs. 1 and 2,'the principal difference being that in the apparatus illustrated in Fig. 3 the asbestos fibers are distributed over the glass fibers as they lie in web form, prior to being drafted into a sliver. In the drawing, reference character 45 designates a glass filament or fiber forming apparatus adapted to produce a. multiplicity of fine fibers 46 by means of a gaseous blast emanating from the blowers 41. The gaseous blast carries the fibers downwardly and deposits them upon a perforated or foraminous screen belt 48 upon which the fibers accumulate in intermatted or web form. The gaseous blast passes directly through the screen belt 48 and into a suction chamber 49 which may be used to assist the deposition and retention of the fibers upon the belt 48. A blower B, communicating with the chamber 49, may also be provided in order to exhaust the gases from the suction chamber. As the fibers 46 lie upon the belt 48 in the form of a thin mat or web 50, they may be sprayed, if desired, with a suitable adhesive or hinder by means of an applicator SI of any suitable design. In practice, the adhesive application may be made before or after deposition of the glass fibers into web form, or during the drafting operation into sliver form.

Mounted over the web 50 is a feeder 53 adapted to deposit a multiplicity of asbestos fibers 54 in a layer overlying and partially in- The feeder 53 may be of any suitable type, as a vibrating belt or the A hopper 55 containing the asbestos may be mounted over the feeder 53; and the hood or chute 56 may also be provided in order to assure passed over the diablo-shaped rolls 58 having a V-shaped, cross-section exposed to the sliver. adapted to fold the sliver and compact it more completely into the form of a strong, compact strand. From here the strand59 may be passed through a traverse 60 and wound upon the spool 6| into the form of a package. The ultimate result again .is a strand composed of intermingled glass and asbestos fibers, which may be handled with any of the usual processes in the formation of intertwisted yarns, ply yarns, and interwoven fabrics.

Referring now to Fig. 4, I have illustrated an other embodiment of the present invention, adapted to produce yarns of combined glass and asbestos fibers.

' In the drawing, reference character 63 desig'- nates a traveling perforated surface, similar to the screen I! of Fig. 1, or like the screen belt .48

of Fig. 3, upon wlich a web 65 of fine glass fibers has been arrested and collected. The web 65 is drawn into the form of a sliver through the trumpet 66 and then over a suitable folding device Bl which may be in-the form of a diabloshaped roll having a V-shaped, cardioid, or heart-shaped cross-section exposed to the sliver.

Mounted in conjunction with the roll 61 'is' a guide 68 arranged at the opening ofthe V and adapted to guide an asbestos roving, yarn, or thread 69 thereunder and into the partially open fold of the glass sliver. The sliver is advanced in semifolded form beneath a guide 12 of arcuate cross-section whereby the upstanding folds of the sliver may be closed over and around the central yarn to substantially surround the same. The roving or yarn 69 may be fed from a package 10 mounted upon the shaft II, or the like.

The folding device performs the dual function of compacting the glass sliver, which more generally is in the form of a more or less flat ribbon, into a more nearly round, compact cross-section,

and simultaneously incorporating the asbestos characteristics above noted in connection with the present invention.

All of the yarns or threads produced by the various specific methods illustrated and described in the present application may be interwoven into the form of a fabric as illustrated, for example, in Fig. "7. The warp yarns 13 may be composed of the same type of yarns as the filler yarns I4, or, if desired, they may be of different varieties, combinations or permutations of any of the yarns illustrated herein. It is also to be noted that the warp yarns 13, if desired, may be. com posed wholly of asbestos, and the filler yarn -'|4 may be composed wholly of glass fibers, or, if desired, either one or both may be composed of combinations of the two.

Modifications and variations may be resorted to within the spirit and scope of the present invention.

I claim: a

1. The method of producing a sliver composed .of combined glass and; asbestos fibers, which comprises forming an open web of long, fine glass fibers, distributing a mass of asbetos fibers into said open web, and drafting said web together to close the intervenin spaces between .the fibers and permit interjacent asbestos fibers to be seized and interfelted therewith in a compact mutually interfelted coherent sliver.

' tertwisting said sliver into a twisted yarn.

3. The method of producing a sliver composed of combined glass and asbestos fibers, which comprises forming an open web of long, fine glass fibers, applying a binder substance to said web, distributing a mass of asbestos fibers throughout said open web, and drafting said web together to. close the intervening spaces between the fibers and permit interjacent asbestos fibers to be seized and interfelted'therewith in a compact mutually interfelted coherent sliver.

4. The method of producing a yarn composed of combined glass and asbestos fibers, which comprises forming an open web of long, fine glass fibers, applying a binder substance to said web, distributing a mass of asbestos fibers within said open web, drafting said web together to close the intervening spaces between the fibers and permit interjacent asbestos fibers to be seized and interfelted therewith in a compact mutually interfelted coherent sliver, and intertwistin'g said sliver 11' into a twisted yarn.

5. The method of producing a sliver composed of combined glass and asbestos fibers, which comprises forming an open web of long, fine glass fibers by depositing said fibers from a gaseous blast, drafting said web into sliver form and closcause them to become. interfelted with said glass,

fibers into a coherent sliver.

6. The method of producing a sliver composed of combined glass and asbestos fibers, which comprises forming an open web of long, fine glass fibers by depositing said fibers from a gaseous blast, drafting said web into sliver form and closing up intervening spaces between said fibers, and

introducing into said web as it is being drawn into sliver form a multiplicity of asbestos fibers ing up intervening spaces between said fibers,

applying a binder to said glass fibers, introducing into said web as it is being drawn into sliver form a multiplicity of asbestos fibers lying parallel to one another, and causing said asbestos fibers to interfelt and intermat with said glass fibers. V

8. The method of producing a strand composed of combined glass and asbestos fibers, which comprises forming an open web of long, fine glass fibers, draftingsaid web in a ribbon sliver form, folding said ribbon longitudinally upon itself and simultaneouslygintroducing into the interior of said fold a strand of asbestos fibers, and causing said ribbon to form a covering for said asbestosfibers.

DONALD SIMPSON. 

